Reversing mechanism

ABSTRACT

A gear drive reversing mechanism is disclosed for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a contant direction. A gear drive reversing mechanism is also disclosed for driving two output shafts in mutually opposite rotary directions by means of a drive shaft rotating in a constant direction. The mechanisms include spiral angle face gears driven by pinions having both right-hand and left-hand spiral angle pinion gear teeth.

United States Patent [1 1 Nickstadt REVERSING MECHANISM [75] Inventor:Gerhard Nickstadt, Oakland, NJ.

[73] Assignee: General Electric Company, Fort Wayne, Ind.

[22] Filed: Aug. 30, 1972 [21] Appl. No.: 284,946

[52] US. Cl 74/404, 74/355, 74/459.5, 74/342 [51] Int. Cl. Fl6h 57/00,Fl6h 3/14, Fl6h 55/04 [58] Field of Search 74/355, 665 GB, 665 GD,74/459.5, 457-459, 342, 376, 404

[451 May 28, 1974 1,330,740 2/1920 Mills 74/355 1,455,706 5/1923 Boweret a1 74/459.5

1,947,853 2/1934 King 74/458 UX 2,190,856 2/1940 Young 74/355 X2,453,656 11/1948 Bullard 74/462 X 2,878,690 3/1959 Capron et a1. 74/355X 3,178,955 4/1965 Enders et a1 74/361 Primary ExaminerArthur T. McKeon[57] ABSTRACT A gear drive reversing mechanism is disclosed forreversing the direction of rotation of an output shaft driven by a driveshaft rotating in a contant direction. A gear drive reversing mechanismis also disclosed for driving two output shafts in mutually oppositerotary directions by means of a drive shaft rotating in a constantdirection. The mechanisms include spiral angle face gears driven bypinions having both right-hand and left-hand spiral angle pinion gearteeth.

10 Claims, 7 Drawing Figures PATENTEDKAY 28 1924 sum 1 BF 3 FIG,5

PATENIEI] I" 2 8 i974 SHEET 3 BF 3 FIG BACKGROUND OF THE INVENTION Thisinvention relates generally to drive reversing mechanisms, andparticularly to drive reversing mechanisms of the types which employ oneor more sets of gears. Thus, it is a general object of the invention toprovide an improved drive reversing mechanism.

More specifically, it is an object of the invention to provide amechanism for reversing the direction of rotation of an output shaftdriven by a rotatable drive shaft without need for reversing thedirection of rotation of the drive shaft.

Another object of the invention is to provide a mechanism for reversingthe direction of rotation of an output shaft driven by a rotatable driveshaft without need for shifting the drive shaft axially or radially.

Another object of the invention is to provide a mechanism for reversingthe direction of rotation of an output shaft driven by a rotatable driveshaft without need for shifting the output shaft radially.

Another object of the invention is to provide a gear drive reversingmechanism which does not require inclusion of an idle gear.

Another object of the invention is to provide a drive reversingmechanism which is inexpensive to construct consisting of a relativelyfew number of easily assembled parts.

Another object of the invention is to provide a gear SUMMARY OF THEINVENTION In one form of the present invention a gear drive reversingmechanism is provided for reversing the direction of rotation of anoutput shaft driven by a drive shaft rotating in a constant direction.The mechanism comprises a drive pinion secured to the drive shaft andhaving both right-hand and left-hand spiral angle gear teeth. A firstface gear having spiral angle gear teeth is mounted to the output shaftfacing the drive pinion. A second face gear having spiral angle gearteeth is also mounted to the output shaft facing the first face gearwith the drive pinion rotatably positioned between the first and secondface gears. The teeth of the first and second face gears are spacedapart a distance greater than the width of said pinion disposed betweenthe first and second face gears wherebyonly one of the face gears may bein mesh with the pinion at any one time. Means are also provided formoving the face gears into and out of mesh with the pinion whereby thedirection of rotation of the output shaft rotatably driven by the driveshaft may be reversed while the direction of rotation of the drive shaftand drive pinion remains constant.

In another form of the invention a gear drive reversing mechanism isprovided comprising a first shaft mounted for rotation about a firstshaft axis and a first face gear having right-hand spiral angle facegear teeth mounted to the first shaft. A second shaft is mounted forrotation about a second shaft axis and a second face gear havingleft-handspiral angle face gear teeth is mounted to the second shaft.The mechanism further includes a rotatably mounted pinion havingright-hand spiral angle pinion gear teeth in mesh with the righthandspiral face gear teeth, and having left-hand spiral angle pinion gearteeth in mesh with the left-hand spiral angle face gear teeth.'Rotationof theapinion in a constant direction simultaneously drives the firstand second shafts in mutually opposite rotary directions.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a' perspective view of adrive reversing mechanism embodying principles of the present invention.

FIG. 2 is a bottom plan view of the drive reversing mechanism shown inFIG. I mounted in a housing. The housing and bearings mounted thereinare shown in cross section.

FIG. 3 is a bottom plan view of the drive reversing mechanism shown inFIG. 1 including portions of the housing illustrated in FIG. 2. Relativepositions of selected mechanism components are shifted in FIG. 3 frompositions assumed in FIG. 2 to effect reversing.

FIG. 4 is a side view in elevation of the drive reversing mechanismshown in FIG. 3 with a portion of the mechanism housing shown in crosssection and with one face gear removed for clarity.

FIG. 5 is a side view in elevation of the .drive pinion employed in thedrive reversing mechanism shown in FIG. 1.

FIG. 6 is a cross-sectional view of the drive pinion shown in FIG. 5taken along plane 66.

FIG. 7 is a diagrammatical view of a modified form of the drivereversing mechanism shown in FIG. 1 embodying another form of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in more detail tothe drawing and in particular to FIGS. 1 and 2, there is shown a drivereversing mechanism embodying principles of the present invention andincluding a housing 10 which may be made of aluminum, steel, cast ironor the like. Four threaded holes 12 in the housingprovide means by whicha housing plate may be secured with a gasket held therebetween. A driveshaft 14 is journalled through a ball bearing in the housing. Thebearing comprises a set of annularly disposed balls 15 rotatablydisposed between an inner race 16 and an outer race 18. The two racesare maintained in position by snap ring 20 secured to drive shaft 14, bysnap ring 21 disposed within an annular recess in the housing, by shaftshoulder 22, and by housing shoulder 24. The terminal end of the driveshaft is journalled in bushing 25 mounted in a housing wall oppositethat in which the ball bearing is disposed.

Drive shaft 14 includes a truncated, conic drive pinion 26, the detailsof which may be seen most clearly by reference to. FIGS. 5 and 6. Thepinion includes both right-hand spiral angle gear teeth and left-handspiral angle gear teeth, which are longitudinally coextensive along thepinion. Shaft 14 and pinion 26 are preferably made of carbonized andhardened steel with the pinion teeth being formed by grinding. The shaftand pinion are preferably of unitary construction.

An output shaft 30 is journalled through support bearings mounted withinopposing walls of housing 10,

which bearings comprise bronze bushings 32 and 33. Output shaft 30passes above drive shaft 14 within the housing cavity with the axes ofthe two shafts oriented substantially normal to each other. Two facegears 35 and 37 are rigidly secured to output shaft 30 with pinion 26disposed therebetween. The two face gears are spaced apart a distancesufficiently great to insure that only one of the face gears engages thedrive pinion at any given time. As will hereinafter be explained in moredetail, the output shaft and face gears are adapted to be moved axiallyto bring face gears 35 and 37 alternatively into mesh with drive pinion26.

The teeth of face gear 35 are right-hand spiral angles while those offace gear 37 are left-hand spiral angles. They, as well as the outputshaft to which they are secured, are formed of hardened steel. Such facegears may be purchased from the Illinois Tool Works Inc. of Chicago,Illinois which, in combination with tapered pinions, are sold under thetrademark Spiroid".

With reference next to FIGS. 1, 3, and 4, means for moving face gears 35and 37 alternatively into and out of mesh with drive pinion 26 are showncomprising an annular cam 40 mounted to the end of control rod 42. Cam40 is mounted to the control rod in sliding contact with hubs 38 and 39of face gears 37 and 35, respectively, and with the cam axis offset fromthat of the control rod. Where mechanical play is desired, the cam ismounted in contact with only one face gear at one time.

Cam mounting is accomplished by means of pin 44 whichv is press fittedinto aligned channels within the cam and control rod. A crosspiece 45 ispress fitted in pin 44 and control rod 42 to inhibit axial movement ofthe pin. Rod 42 is journalled through bushing 47 mounted within housingto the housing exterior.

As a final assembly step, a housing cover is secured and the housinginterior then partially filled with a lubricating oil. Lubrication isfacilitated by the presence of both left-hand and right-hand spiralangle pinion gear teeth which are longitudinally coextensive.

In operation, drive shaft 14 may be rotated unidirectionally such asclockwise as indicated by arrow 50 with drive pinion in mesh withright-hand spiral angle face gear 37 as seen in FIGS. 1 and 2. Theresultant torque transmitted to the face gear causes it and output shaft30 to rotate clockwise as indicated by arrows 55. Should reverserotation become desired, rotation of the drive pinion and output shaftis momentarily halted and rod 42 rotated a half turn. This action causescam 40 to force the face gears and output shaft to move axially. As theface gears move, gear 37 disengages drive pinion 26. As the half turn ofthe rod and cam is completed, left-hand spiral angle face gear 35engages the drive pinion, Mesh will ordinarily occur with higher gearingratios whereas with lower ratios conventional spring bias may be appliedto the face gears to'insure m'esh upon recommencenient of pinionrotation. With pinion 26 now in engagement with face gear 35, clockwiserotation is again imparted to the drive pinion causing output shaft 30to be driven counterclockwise as indicated by arrow 51 in FIGS. 1 and 4and with the mechanism components assuming the relative positionsdepicted in FIGS. 3 and 4. To return the rotation of the output shaftback to its original direction rod 42 is merely rotated another halfturn causing face gear 35 to disengage the drive pinion and face gear 37shortly thereafter to reengage the pinion while rotation of the drivepinion and face gears is momentarily arrested.

For some applications avoidanceof axial movement 7 of the output shaftmay be desired. Under such circumstances face gears 35 and 37 may berigidly secured to a tubular sleeve about shaft 30 thereby permittingrelative axial movement between the face gears and output shaft uponrotation of cam 40. In such cases rotational slippage of the face gearsupon the shaft is prohibited or limited by keys and keyways, or bymeshed, coaxial teeth formed on the exterior of the shaft and interiorof the tubular sleeve.

FIG. 7 illustrates another embodiment of the invention which may beconstructed through a modification of the drive reversing mechanism justdescribed. Here, rather than reversing the direction of a single outputshaft, two independent, coaxial, output shafts 60 and 62 aresimultaneously driven in opposite directions as indicated by arrows 5and 55, respectively. Each is simultaneously in mesh with drive pinion26. Again, face gear 37 is right-hand spiral angle while face gear 35 isleft-hand spiral angle.

It should be understood that the just described embodiments merelyillustrate principles of the invention. Many other modifications may bemade thereto without departure from the spirit and scope thereof as setforth in the following claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is: v

l. A gear drive reversing mechanism for reversing the direction ofrotation of an output shaft driven by a drive shaft rotating in aconstant direction, said gear drive reversing mechanism comprising atapered drive pinion rotatable with said drive shaft, with said tapereddrive pinion having both right-hand spiral angle gear teeth andleft-hand spiral angle gear teeth, a first face gear drivingly connectedwith said output shaft and having spiral angle gear teeth facing saiddrive pinion; a second face gear drivingly connected with said outputshaft and having spiral angle gear teeth facing said first face gearwith said drive pinion rotatably positioned between said first andsecond face gears; the teeth of said first and second face gears beingspaced apart a distance greater than the width of said drive piniondisposed between said first and second face gears whereby only one ofsaid first and second face gears may be in mesh with said drive pinionat any one time; and means for moving said first and second face gearsinto and out of mesh with said drive pinion whereby the direction ofrotation of said output shaft rotatably driven by said drive shaft maybe reversed while the direction of rotation of said drive shaft anddrive pinion remains constant. 7

2. A gear drive reversing mechanism in accordance with claim 1 whereinsaid first and second face gears are rigidly mounted to said outputshaft.

3. A gear drive reversing mechanism in accordance with claim 1 whereinsaid moving means comprises a cam supported for contact with said firstand second face gears.

4. A gear drive reversing mechanism in accordance with claim 1 whereinsaid right-hand spiral angle gear teeth and said left-hand spiral anglegear teeth are longitudinally coextensive along said pinion.

5. A gear drive reversing mechanism for reversing the direction ofrotation of an output shaft being driven by a drive shaft rotating in apredetermined direction, said reversing mechanism comprising a tapereddrive pinion rotatably with said drive shaft; said tapered drive pinionhaving a right hand spiral groove in the surface thereof, and aleft-hand spiral groove in the surface thereof traversing saidright-hand spiral groove to form a plurality of pinion gear teethbetween said grooves; a first face gear coupled to said output shaft andhaving spiral gear teeth facing said pinion gear teeth; a second facegear coupled to said output shaft and having spiral gear teeth facingsaid pinion gear teeth; and means for holding the spiral gear teeth ofsaid first face gear in engagement with said pinion gear teeth when thespiral gear teeth of said second face gear are disengaged from saidpinion gear teeth, and for holding the spiral gear teeth of said secondface gear in engagement with said pinion gear teeth when the spiral gearteeth of said first face gear are disengaged from said pinion gearteeth; said output shaft being rotatably drivable by said input shaft inopposite directions without reversing the direction of rotation of saiddrive shaft.

6. A gear drive reversing mechanism in accordance with claim 5 whereinsaid drive pinion is secured to said drive shaft for rotation about afirst axis, said first and second face gears are coupled to said outputshaft for rotation about a second axis, and said first and second axesoverlay one another at substantially right angles.

7. A gear drive reversing mechanism in accordance with claim 5 whereinsaid engaging means comprises a cam supported for contact with at leastone of said face gears.

8. A gear drive reversing mechanism comprising a shaft mounted forrotation about a shaft axis; a first face gear mounted to said shaft andhaving right-hand spiral angle gear teeth; a second face gear mounted tosaid shaft in spaced relation with said first face gear and havingleft-hand spiral angle gear teeth facing said right-hand spiral anglegear teeth of said first face gear; a tapered pinion mounted betweensaid first and second face gears for rotation about a pinion axisdisposed substantially at a right angle with said shaft axis, saidtapered pinion having both right-hand spiral angle gear teeth faces thatdefine a right-handspiral groove and left-hand spiral angle gear teethfaces that define a lefthand spiral groove; and means for alternativelyengaging teeth of said pinion with the teeth of said first and secondface gears.

9. A gear drive reversing mechanism in accordance with claim 8 whereinsaid right-hand spiral angle gear teeth and said left-hand spiral anglegear teeth are longitudinally coextensive along said pinion.

10. A gear drive reversing mechanism in accordance with claim 8 whereinsaid alternative engaging means comprises a cam positioned between saidfirst and second face gears.

1. A gear drive reversing mechanism for reversing the direction ofrotation of an output shaft driven by a drive shaft rotating in aconstant direction, said gear drive reversing mechanism comprising atapered drive pinion rotatable with said drive shaft, with said tapereddrive pinion having both right-hand spiral angle gear teeth andleft-hand spiral angle gear teeth; a first face gear drivingly connectedwith said output shaft and having spiral angle gear teeth facing saiddrive pinion; a second face gear drivingly connected with said outputshaft and having spiral angle gear teeth facing said first face gearwith said drive pinion rotatably positioned between said first andsecond face gears; the teeth of said first and second face gears beingspaced apart a distance greater than the width of said drive piniondisposed between said first and second face gears whereby only one ofsaid first and second face gears may be in mesh with said drive pinionat any one time; and means for moving said first and second face gearsinto and out of mesh with said drive pinion whereby the direction ofrotation of said output shaft rotatably driven by said drive shaft maybe reversed while the direction of rotation of said drive shaft anddrive pinion remains constant.
 2. A gear drive reversing mechanism inaccordance with claim 1 wherein said first and second face gears arerigidly mounted to said output shaft.
 3. A gear drive reversingmechanism in accordance with claim 1 wherein said moving means comprisesa cam supported for contact with said first and second face gears.
 4. Agear drive reversing mechanism in accordance with claim 1 wherein saidright-hand spiral angle gear teeth and said left-hand spiral angle gearteeth are longitudinally coextensive along said pinion.
 5. A gear drivereversing mechanism for reversing the direction of rotation of an outputshaft being driven by a drive shaft rotating in a predetermineddirection, said reversing mechanism comprising a tapered drive pinionrotatably with said drive shaft; said tapered drive pinion having aright-hand spiral groove in the surface thereof, and a left-hand spiralgroove in the surface thereof traversing said right-hand spiral grooveto form a plurality of pinion gear teeth between said grooves; a firstface gear coupled to said output shaft and having spiral gear teethfacing said pinion gear teeth; a second face gear coupled to said outputshaft and having spiral gear teeth facing said pinion gear teeth; andmeans for holding the spiral gear teeth of said first face gear inengagement with said pinion gear teeth when the spiral gear teeth ofsaid second face gear are disengaged from said pinion gear teeth, andfor holding the spiral gear teeth of said second face gear in engagementwith said pinion gear teeth when the spiral gear teeth of said firstface gear are disengaged from said pinion gear teeth; said output shaftbeing rotatably drivable by said input shaft in opposite directionswithout reversing the direction of rotation of said drive shaft.
 6. Agear drive reversing mechanism in accordance with claim 5 wherein saiddrive pinion is secured to said drive shaft for rotation about a firstaxis, said first and second face gears are coupled to said output shaftfor rotation about a Second axis, and said first and second axes overlayone another at substantially right angles.
 7. A gear drive reversingmechanism in accordance with claim 5 wherein said engaging meanscomprises a cam supported for contact with at least one of said facegears.
 8. A gear drive reversing mechanism comprising a shaft mountedfor rotation about a shaft axis; a first face gear mounted to said shaftand having right-hand spiral angle gear teeth; a second face gearmounted to said shaft in spaced relation with said first face gear andhaving left-hand spiral angle gear teeth facing said right-hand spiralangle gear teeth of said first face gear; a tapered pinion mountedbetween said first and second face gears for rotation about a pinionaxis disposed substantially at a right angle with said shaft axis, saidtapered pinion having both right-hand spiral angle gear teeth faces thatdefine a right-hand spiral groove and left-hand spiral angle gear teethfaces that define a left-hand spiral groove; and means for alternativelyengaging teeth of said pinion with the teeth of said first and secondface gears.
 9. A gear drive reversing mechanism in accordance with claim8 wherein said right-hand spiral angle gear teeth and said left-handspiral angle gear teeth are longitudinally coextensive along saidpinion.
 10. A gear drive reversing mechanism in accordance with claim 8wherein said alternative engaging means comprises a cam positionedbetween said first and second face gears.